1. Field
One embodiment of the present invention relates to a wireless communication device which is used in an ad-hoc network including a plurality of devices which execute wireless communication, a wireless communication system and a network control method.
2. Description of the Related Art
In recent years, a wireless communication system, which makes use of an ad-hoc network, has been developed.
In the ad-hoc network, any one device selected from devices, which are present in the ad-hoc network, functions as a coordinator. The coordinator controls the entire ad-hoc network.
Jpn. Pat. Appln. KOKAI Publication No. 2006-50636 discloses a method of selecting a coordinator from a plurality of nodes (devices) which constitute an ad-hoc network.
In this method, the coordinator is selected from the nodes by using (a) a maximum coverage range, (b) a maximum capacity and (c) a device class, as standards for selection.
In the coordinator selection method of Jpn. Pat. Appln. KOKAI Publication No. 2006-50636, however, no consideration is given to which of the devices a user wishes to use. Thus, depending on the selected coordinator, it is possible that the device which the user wishes to use is not included in the communication range that is covered by the selected coordinator, and the device which the user wishes to use cannot execute wireless communication with other devices.
In a wireless communication system using radio waves of a millimeter-wave band in order to realize high-speed data transmission, the rectilinearity of propagation of the radio waves is very high, and the wireless communication environment between devices greatly varies depending on the positional relationship between the devices and the presence/absence of an obstacle between the devices.
In the wireless communication system using the radio waves of the millimeter-wave band, it is highly possible that there is a device which cannot execute wireless communication with the coordinator, that is, a device which cannot take part in the ad-hoc network.
Therefore, there is a need for a technique for reconfiguring an ad-hoc network so as to constitute a network centering on a certain specified device such as a device which the user wishes to use.